Plastic snap hinge



Dec. 25, 1951 R. l= MAGNENAT PLASTIC SNAP HINGE Filed oct. 14, 1949 2 SHEETS-SHEET l Z wHNldlxlli-lili-- r I. Y A

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@5A/E H MAGNENA 7 A TT'ORNE Y Dec. 25, 1951 R. P. MAGNENAT 2,580,310

PLASTIC SNAP HINGE Filed Oct. 14, 1949 2 SHEETS-SHEET 2 IN VEN TOR. RENE R MAG/VE/VAT ATTORNEY Patented Dec. 25,Y 1951 PLASTIC SNAP HINGE Ren P. Magnenat, Waterbury, Conn., assignor to Waterburyv Companies, Incorporated, Waterbury, Conn., a corporation of Connecticut Application `October 14, 1949, Serial No. 121,337 4 claims. (ci. 22o-s1) l This invention relates to a hinge structure for receptacles having swingable covers of molded plastic material, and more particularly to a hinge structure having a double-acting spring which is adapted to urge the receptacle cover selectively either to open or closed position with a snap action.

One object of this invention is to provide a device of the above nature in which the spring will serve both for swinging the cover and for holding the cover in assembled relation with the base of the receptacle.

.Another object is to provide a receptacle in which the edges'of the cover and the base have auxiliary interengageable means for holding the hinge connection assembled when the cover is in closed position.

A further object is to provide a device of the above nature which will be simple in construction, inexpensive to manufacture, easy to assemble and manipulate, compact, ornamental in appearance, and very eicient and durable in use.

With these and other objects in view, there have been illustrated on the accompanying drawing twoforms in which the invention may conveniently be embodied in practice.

In the drawing,

Fig. 1 is a plan view of a receptacle embodying theiirst form of the improved plastic snap hinge, and showing the cover in closed position.

Fig. 2 is a side view of the same.

Fig. 3 is a front view of the same.

Fig. 4 is a cross sectional view on an enlarged scale, taken on the line 4-4 of Fig. 1.

Fig. 5 is a fragmentary perspective view on a .L

still larger scale, showing the hinge partly in section. Fig. 6 is a cross sectional view, similar to a portion of Fig. 4, but showing the hinge structure as it would appear with the cover open.

' Fig. 7 is a fragmentary perspective view showing a second form of the improved snap hinge.

Referring now to the drawings in which like reference numerals denote corresponding parts throughout the several views, the numeral I indicates a receptacle base having a at bottom wall I I and a peripheral wall I2, and the numeral I3 indicates a cover having a top wall I4 and a peripheral wall I5. The outlines of the base Ill and the cover I3 are of the same general size and shape, so that when the cover I3 is closed the peripheral wall I will be disposed in valigned structure abutting relationship with the peripheral wall -I2 lof thebase I0. f y .A portion of the peripheral wall I2 at the rear of the base I0 is outwardly oiiset so as to provide an inwardly concave bracket portion I6, the upper side portions of which are curved forwardly in tangent relationship to the upper edge of the wall I2, so as to provide sho-rt bearing anges II, I8 separated by a rectangular slot I9 in the upper edge of the bracket portion I6.

The rear of the peripheral cover wall I5 is provided with an integral depending lug 20 which has a substantially cylindrical surface curvature, and which is of suitable dimensions to close the slot I9 in all normal positions of the cover I3.

The lug 20 has a pair of reduced cylindrical side trunnions 2l 22 which are adapted to underlie and be retained in position against the lower surfaces of thebearing flanges II, I8, so that l the cover I3 may swing about said trunnions 2|,

22 `from the closed position shown in Fig. 4, to the open position indicated in Fig. 6.

The cylindrical lug 20 is preferably provided with an outer horizontal projecting shoulder or abutment 23 which is adapted to engage the lower end of the slot I9, and thus serve as a stop to Alimit opening movement of the cover I3.

In order to retain the trunnions 2l, 22 against the flanges I'I, I8, provision is made of a U-shaped .wire spring 24 having a straight horizontal centrai section 25 engaged in a longitudinal slot 26 in the lower surface of the lug 20. The sides of the U-shaped wire spring 24 comprise a pair of upwardly concave side arms 21, 28 which terminate at their lower ends in aligned outturned portions 29,30. t In order to anchor the outturned ends 29, 39 of the U-shaped spring 24, the interior of the receptacle base I0 is integrally provided with raised bosses 3|, 32 extending forwardly from the peripheral wall I2 at opposite sides of the bracket wall portion I6. The upper surfaces of the bosses 3|, 32 are formed with respective aligned open-topped grooves 33, 34, in which the outturned spring ends 29, 30, are received, and which are so located as to hold the U-shaped spring 24 in a compressed condition in which the curved spring side arms 21, 28 are resiliently bent. Y f

It will be noted that the'parts are so arranged that the slot 26 is disposed at the lowermost portion of the cylindrical lug 29 when the cover I3 is in horizontal or closed position, while the axis of the trunnions 2|, 22 is sodisposed above said slot 26 that a plane including said axis and the grooves 33..'34 is inclined at an angle of approximately degreestothe horizontal'.y l fj Thus,- the U-shaped wire-spring y24 Willnot only hold the trunnions 2| 22 in engagement with the bearing flanges I1, I8 when the cover I3 is closed, but will also provide a toggle action urging said cover I3 either to closed or to open position, depending upon the position of said cover in its swinging movement. For example, the compressive force of the spring 24 will tend to hold the cover I3' open when said cover is. in the position shown in Fig. 6, while the cover will be held closed when in the position shown vin Fig. 4.

In order to provide additional detentv means for holding the trunnions 2|, 22 in engagement with the bearing flanges I1, I8 when the cover I3 is in closed position, the lower tfront edge of said cover is provided with a depending nose 35 which is ad-apted to engage-in a correspondingv recess 36 in the front of the receptacle base I0.

Thus, accidental separation or misali'gnment of the cover I3 with the base Il) will positively be prevented while said cover is in closed position.

When the cover I3 is-open, as shown in Fig. 6 lfor example, separation of the trunnions 2|., 22 from' the: bearing flanges I1,. I8 will be positively prevented by virtue of the Ifact that. lower edge portions of the peripheral wall I will overlie vthe outer downwardly curved` surfaces of. the

bearinganges I1, I 8.r

Inzorder to accomodate. and to conceal the lug 35 andA the. recess236 at. the 'frontfof the receptacle.. the. basel Il!V and cover I3 preferably have. complementary" outer bosses 31,38. Provision. is also made. of relatively small lateral bossesi 39, 40, which extend to'the left of. the boss 38, andthe rightofathe boss. 3.1, respectively, in order. to serve as. fingerr pieces for facilitating the. openingof the receptacle.

Assembly offrst'form' 11nv 'asser'nbly-y thescover I3v will be brought'rtoward the receptacle base: I0 in' a position forwardly ofset fromth'e nal assembled position of said cover, and suiiiciently separated from thevfront of the base: I0 to enable the nose 35 'to cle-ar the upper edge-of thebo'ss31.

In this offset position the-trunnions 2I, 22 will be disposed just forwardly of the bearing flanges I1,v I8,` and said trunnions may'now be slid under said flanges merely by pressing the vcover I3 rear'- wardly with respect to thev base I0. The cover I3 will nowV be openedto the position shown in Fig. 6, and the outturned end portions-29, 30 of the spring 2'4 will loe-inserted inthe grooves 33, 34.

The.: straight 'centrar section". 25. of the spring 24`will then' beA pressed downwardly over the' sur@ face of thecylindrical lug until said central sectiontsnap's into the' slot 26,*whereupon assembly Willbe complete;

The cover I3 may now'becl'osed'by swinging itrdownwardly, this'. actionresultin'g in compression of the spring 24 until suchtime as Ythe straight 'spring section- 25 has -passed the dead 'center position in whichthe coverVv I3 is disposed at approximately 45 degrees to the base I0.

Thei tendency-of.' the; curved spring` arms' 21, 28 to straighten will then causethe spring'A 24 to expand, thus urging' the cover I3 to the completely closed position shown in Fig. 4.

When the cover' I 3 is in closed position, the nose One advantage of the first form of the invention is that the curved shape of the spring arms 21, 28 will afford clearance for objects which may be contained within the box.

- said spring.

In the second form, provision is made of a wire l spring'AI in the form of a broad U which is dis- .35 will beinterengaged witnthe recess: 36, thus holding; the: cover.. I.3.a:lig,x1ed. with; the:v baseaglll and positively ,p reventingseparationfof .the trims nions 2| 22 from. ther-bearing. angesr. I1., I8;

posed entirely in. a single plane and which comprises a Vshort straight central section 42 and straight diverg-ing side arms 43, 44 having outturned terminal portions 45, 46, the latter being received in the grooves 33, 34 in the bosses 3|, 32 of thev base I0.

The peripheral cover" wall I5 is provided with a modified, generally cylindrical depending lug 41, the lower portion of which has attened segmental end zones 48, 49, thus providing a down- Ward central projection 50 of approximately the same length as the central spring section 42.

The central spring section 42 is disposedk in a longitudinal slot 5I in the lower surface of the lug projection 50, so that the spring arms 43, 44 will be. disposed at the end zones 48, 49 and will be sWingable at opposite ends.v of the pro- 4jection 50.

Assembly of second form In assembly, the trunnions 2l, 22', will be' slid under the bearing flanges I1, I8, and the cover I3 will then be opened, as in the assembling of the iirst form of the invention. The terminal portions 45, 46 of the spring 4I will then be placed in the grooves 33, 34, respectively, and the central spring section 42 will be brought against Vthe surface of the lug projection 53 and pressed downwardly until it snaps into the slot 5I, whereupon the hinge structure will be completely assembled, and the box cover I3 may be repeatedly opened and closed as desired. The dead center position of the cover I3 will occur when said cover is disposed at approximately 45 degrees to the base II), the diverging relationship of the spring arms 4.3, 44 permitting the spring 4I to bend and be compressed in this position of the cover I3. Thus, itwill. be seen that the assembly and operation of the second form of the invention will be substantially the same' as the assembly and operation of the first form. Y y

One advantage of both forms of the'improved hinge' structure herein disclosed Aisits ease vof assembly, whereby the receptacles vembodying said hinge structure may b'e'very economically manufactured.

While there have' been disclosed in this specification two forms in which the invention may be embodied, it' is to be understood that. these forms are shown for the purpose of .illustration only,` and that the invention is not to be limited to the. specific disclosure,v but may be modified Y a peripheral wall integral with and upstanding from said base, said peripheral wall comprising a rearwardly off-set bracket portion having a slot in its upper edge, a molded plastic cover for said base comprising a depending lug disposed within said slot, said bracket portion extending forwardly at opposite sides of said slot to provide a pair of short flanges having downwardly and forwardly facing horizontal bearing surfaces, a pair of aligned trunnions integral with opposite ends of said depending lug and underlying said bearing surfaces, a shallow substantially U- shaped spring within said container having opposed outwardly projecting end portions, means centrally located at the outer end of said depending lug and olf-set from said trunnipns for holding the central portion of said spring, and means within said base and aligned with and forward of said rst spring retaining means for constraining the outwardly projecting end portions of said spring against inward movement with respect to said base without interfering with sidewise expansion of said end portions, whereby said spring will have a snap toggle action urging said cover selectively toward open and closed positions.

2. The invention as defined in claim 1 in which wardly convex.

REN P. MAGNENAT.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,697,074 Lorentzen Jan. 1, 1929 2,203,960 Hickman June 11, 1940 2,370,928 Baldanza Mar. 6, 1945 2,442,873 Graham June 8, 1948 FOREIGN PATENTS Number Country Date 19,005 Austria Jan. 25, 1905 

